Packing machine

ABSTRACT

In a packaging machine in which an intermittently fed tube of packaging material is filled with a pourable substance and subdivided into individual packages by pinching the tube and transversely sealing it at intervals along its length, the combination of a pair of sealing jaws for intermittently applying a transverse sealing zone to the tube, a pair of severing blades for severing a filled and sealed leading portion of the tube by cutting through the said sealing zone to leave the then leading tube end sealed, closure means operative intermittently to pinch the tube shut upstream of the said sealing zone and thereby intermittently interrupt the flow of pourable substance, and clamping means effective to clamp and support the leading tube end at the said sealing zone when the closure means are inoperative.

United States Patent Reil PACKING MACHINE Wilhelm Reil, Bensheim-Auerbach, Germany Inventor:

[73] Assignee: Sabrefina S.A., Fribourg,

Switzerland Filed: July 2, 1971 Appl. No.: 159,330

[ June 12, 1973 Primary Examiner-Robert L. Spruill Attorney-David Toren and Bernard X. McGeady [57] ABSTRACT In a packaging machine in which an intermittently fed tube of packaging material is filled with a pourable substance and sub-divided into individual packages by pinching the tube and transversely sealing it at intervals along its length, the combination of a pair of sealing jaws for intermittently applying a transverse sealing zone to the tube, a pair of severing blades for severing a filled and sealed leading portion of the tube by cutting through the said sealing zone to leave the then leading tube end sealed, closure means operative intermittently to pinch the tube shut upstream of the said sealing zone and thereby intermittently interrupt the flow of pourable substance, and clamping means effective to clamp and support the leading tube end at the said sealing zone when the closure means are inoperative.

9 Claims, 2 Drawing Figures I uzminm 3.738.080

SHEH 1 0f 2 INVENTOR wuuum Rm PAIENIEU 3.738080 sum 2 or 2 INVENTOR WILHELM REIL 1 PACKING MACHINE The invention relates to a packaging machine in which a tube of packaging material is filled with pourable substance and sub-divided into individual packages by pinching the tube and transversely sealing it at intervals along its length.

In the packaging art, packages are often made by forming a flat web of packaging material to tubular shape, joining the longitudinal edges of the web to each other to form a closed tube and then filling the tube with the pourable substance. As mentioned above, the tube is sub-divided into individual packages or units by applying transverse seals and these units are successively severed from the leading end of the tube by cutting through the transverse seals. In order that the individual packages may be easy to manipulate and easy to store, they are often given a self-retaining geometrical shape, for example a parallelepiped shape.

Packaging machines operating in the abovementioned manner can have a very high productioncapacity, that is to say a large number of packages can be made per unit time. The primary cause for an upper limit to the production capacity is given by the transverse seals because at the sealing zones the packaging material must first be heated to the sealing temperature and then, before the sealing jaws can be disengaged, a certain amount of time must elapse to enable the material to cool until the seals have set sufficiently to withstand the mechanical stresses that are set up during final shaping of each package.

In conventional packaging machines this problem has been solved by providing displaceable sealing jaws which can follow the feeding movement of the tube. This means that the sealing time can overlap with the period during which the tube is fed. However, displaceable sealing jaws are mechanically complicated and relatively expensive and the capacity of the packaging machine cannot be increased decisively because the inertia forces set up during acceleration and deceleration of the sealing jaws place an upper limit on the operating speed.

According to the invention, a packaging machine in which an intermittently fed tube of packaging material is filled with pourable substance and sub-divided into individual packages by pinching the tube and transversely sealing it at intervals along its length comprises a pair of sealing jaws for intermittently applying a transverse sealing zone to the tube, a pair of severing blades for severing a filled and sealed leading portion of the tube by cutting through the said sealing zone to leave the then leading tube end sealed, closure means operative intermittently to pinch the tube shut upstream of the said-sealing zone and thereby intermittently interrupt the flow of pourable substance, and clamping means effective to'clamp and support the leading tube end at the said sealing zone when the closure means are inoperative.

By means of the invention, therefore, the seal is relieved from undue stresses whilst it is still warm and whilst it has not yet reached its full mechanical strength by supporting the tube at its sealed leading end whilst the pourable substance is flowingto that end.

An example of the invention will now be described with reference to the accompanying diagrammatic drawings, wherein:

FIG. 1 is a part-section side elevation of a packaging machine, and

' FIG. 2 is a similar view of the same machine but illustrating the disposition of certain integers during a different stage of a packaging cycle.

Referring to the drawings, a tube 1 of packaging material has an elongated or oblong cross-section and is intermittently fed vertically downwardly through a packaging machine which comprises a pair of sealing jaws 2 for intermittently applying a transverse sealing zone 29 (FIG. 2) to the tube. Closure means are provided upstream of the sealing jaws for intermittently pinching the tube shut. These closure means comprise a fixed jaw 3 and a movable jaw 4 which is pivotable about a shaft 9 by any suitable means (not shown). The lower ends of the closure jaws 3, 4 carry rollers 5 and 6, respectively, which press on one another with the tube 1 compressed therebetween when the jaw 4 is swung towards the jaw 3. The closure jaws also carry guide rolls 7 and 8 which assist transformation of the tube 1 from its oblong cross-sectional shape upstream of the jaws 3 and 4 to its compressed flattened condition when sandwiched between the rollers 5 and 6. The packaging machine further comprises shaping plates 10 which are provided downstream of the sealing jaws 2 and assist in bringing each filled package to a desired final shape.

Severing means 11 are provided downstream of the shaping plates 10 and comprise a pair of severing blades 11, 1 l" of which the blade 1 l" is fixed and the blade 11 movable with respect thereto. The severing blades are associated with respective clamping jaws l2, 13 which are pivotable on shafts 14, 15 carried by mountings 16, 17 which are fixed to the respective blades 11" and 11. The clamping jaw 12 is biassed to a depressed position (see FIG. 2) by a tension spring 18. Similarly, the jaw 13 is under the influence of a tension spring 19 which depresses the jaw 13 whenever the latter is not actuated by a rocker arm 20, this condition being illustrated in FIG. 2. The rocker arm 20 is pivotable about a shaft 21 by means of an actuator 22 which is carried by one of the sealing jaws 2 and therefore moves in synchronism with the sealing jaws. At the downstream end of the packaging apparatus, there is a support 23 for successively filled, sealed and shaped packages 24.

FIG. 1 shows the apparatus when its components are in a position allowing a sealed leading portion 25 of the tube 1 to be filled with a pourable substance. The leading end of the tube is sealed as indicated at 26. A top seal on the finished package 24 is designated 27. In the position of the parts shown in FIG. 2, a compressed portion of the tube after leaving the closure jaws 3, 4 is indicated at 28. The package 24 has been filled, sealed at the sealing zone 29 but is still joined to the flattened tube portion 28.

The operation of the apparatus is as follows:

The tube 1 is, as already mentioned, of oblong crosssection and may have been formed from a flat web of paper having a thermoplastic coating on one side, the web having been brought to its tubular shape and joined at its longitudinal edges (with the thermoplastic coating on the inside of the tube) by equipment which is not illustrated because it is located upstream of the packaging apparatus and does not form part of the present invention. In order that pourable substances to be introduced through the tube may collect in its leading end portion, the leading tube end must of course be sealed as shown at 26 and this end seal is applied as hereinafter described.

A filling tube (not shown) is used to introduce the pourable substance to the top of the tube 1. It is intended that each successive leading portion 25 of the tube be formed to a package of substantially parallelepiped shape, for which purpose the web of packaging material from which the tube 1 is made had already been provided with fold lines such as 30 which make it easier for the package to assume this shape. As soon as a predetermined quantity of pourable substance has reached the leading end portion 25, the shaping of which is assisted by the shaping plates 10, the flow of pourable substance is terminated by swinging the closure jaw 4 towards the fixed closure jaw 3 in a clockwise direction until the roller 6 is pressed against the roller 5, this causing the entire tube to be flattened or pinched across its entire width where it is sandwiched between the rollers and 6. The means for pivoting the closure jaw 4 may comprise a hydraulic cylinder or any other suitable means, for example mechanical means operatively connected to means (not shown) for moving the sealing jaws 2 towards and away from one another.

Simultaneously with or immediately following pinching of the tube at the location of the rollers 5 and 6, the sealing jaws 2 are moved towards one another so as to be applied to the tube 1 which of course remains flattened between the jaws. An electric current of high amplitude is then passed through heating strips 31 of the jaws. The heating strips rapidly become hot and a portion of this heat is conducted through the tube wall so that the inner thermoplastic covering fuses and forms a strong welded seal under the pressure of the sealing jaws 2. During the filling operation, the seal 26 at the leading end of the tube was being clamped and supported between the two clamping jaws l2 and 13, the function of which will hereinafter be described in more detail.

Following formation of the seal by the jaws 2, the latter are separated but the closure jaws 3 and 4 continue to remain in the position where the rollers 5 and 6 prevent the downflow of pourable substance. The severing blades 11' and 1 1" are then moved apart, the clamping jaws 12 and 13 simultaneously being opened to release the seal 26 because, as the jaw 11' is being moved away from the jaw 11", the rocker arm disengages the clamping jaw 13 and allows the latter to become depressed under the action of the tension spring 19. The tube 1 is thereupon fed downwardly through a distance corresponding to the length of each package to be formed, the rollers 5, 6 of the clamping jaws remaining operative to flatten the tube and prevent the downflow of the pourable substance and the guide rolls 7, 8 being effective in assisting the tube to be transformed to its flattened condition. The parts of the packaging apparatus are now in the position shown in FIG. 2 and it will be noted that a filled and sealed package 24 is still connected to the tube 1 by the portion containing the sealing zone 29 that was previously formed by the jaws 2. The package 24 is located on or immediately above the support 23 with the aid of which the package can be transported to a shaping apparatus (not shown) in which the package 24 is brought to its final shape.

After the tube 1 has been fed to the FIG. 2 position, the severing blade 11' is moved towards the fixed blade 11" to cut through the sealing zone 29. This leaves the package 24 in the condition illustrated in FIG. 1, with about half of the sealing zone 29 forming the top seal 27' of the package and the other half sealing the now leading end of the tube 1. Movement of the severing blade 11 towards the blade 11" was also effective to bring the clamping jaws 12, 13 into an overlapping condition, with the jaw 13 positioned below the jaw 12 and the end seal of the tube disposed therebetween but both jaws still being depressed by their respective tension springs 18 and 19. When the sealing jaws 2 are next moved towards one another, the clamping jaw 13 is pivoted about the shaft 15 under the action of the rocker arm 20 which is rotated by the actuator 22. As the clamping jaw 13 is rotated, it also forces the jaw 12 to rotate against the action of the spring 18 and eventually the two clamping jaws will tightly engage and support the end seal 26 of the tube. Before the sealing jaws 2 have closed on the tube 1 but after the clamping jaws l2 and 13 have engaged the end seal 26, the closure jaw 4 is rotated in an anticlockwise direction to separate the rollers 5, 6 and permit some of the pourable substance to flow into the leading portion 25 of the tube as indicated in FIG. 1. The operating cycle is now repeated to form a further package between the shaping plates 10. The static and dynamic pressure exerted by the pourable substance on the leading portion 25 of the tube would normally overload the end seal 26 if there has been insufficient time for this seal to cool and set to its full mechanical strength. By means of the clamping jaws l2 and 13, however, the seal is clamped between the jaws and supported thereby during the filling operation In addition, the bottom of the portion 25 is also supported by the clamping jaws and therefore the seal 26 is relieved from excessive stresses. Accordingly, filling of the portion 25 can commence much earlier than would be possible without the clamping jaws 12 and 13. As the sealing jaws 2 approach one another, the jaws 12, 13 become more elevated until they form a relatively flat surface on which the bottom of the tube portion 25 can rest, the pressure of pourable substance within the portion 25 causing the tube material to bend about the fold lines 30.

It has been found that by means of the packaging machine according to the invention the speed of production can be much higher than hitherto and the strength of the seals 26 of the finished packages are stronger than usual because they are not subjected to mechanical stresses during their cooling period.

It will-be clear that modifications of the apparatus can be made within the scope of the appended claims. For example, the shapes of the finished packages need not be parallelepiped. Also, the rollers 5 and 6 may be replaced by guide rails, although the latter are not as good. Still further, the closure jaws 3, 4 and clamping jaws 12, 13 may function in a different manner, although we are of the opinion that the illustrated arrangement is the best.

We claim:

1. A packaging machine in which an intermittently fed tube of packaging material is filled with a liquid substance and sub-divided into individual packages by pinching the tube and transversely sealing it at intervals along its length, comprising a pair of sealing jaws mounted at a fixed horizontal position for intermittently applying a transverse sealing zone to the tube, a pair of severing blades for severing a filled and sealed leading portion of the tube by cutting through the said sealing zone to leave the then leading tube end sealed, closure means operative intermittently to pinch the tube shut upstream of the said sealing zone and thereby intermittently interrupt the flow of liquid substance, said closure means being operable to effect interruption of said flow as said pinched tube is fed through said operative closure means, clamping means effective to support the leading tube end and to clamp said sealing zone when the closure means are in-operative and the leading tube end is being filled with liquid, whereby said sealing zone is clamped during the filling operation to permit said sealing zone to cool and set and thereby withstand the mechanical stresses caused by the weight of the liquid in the package, and means for opening said clamping means to permit said filled package to be lowered as said pinched tube is fed through said operative closure means.

2. Apparatus according to claim 1, wherein the clamping means comprise two clamping jaws which are pivotable about parallel axes and connected to the severing blades so as to receive the leading tube end between each other when the severing blades have cut through the sealing zone.

3. Apparatus according to claim 2, wherein the closure means comprise two jaws, at least one of which is pivotable to and from the operative position at which the flow of the liquid substance is interrupted.

4. Apparatus according to claim 3, wherein each jaw of the closure means comprises a roller, the rollers being adapted to pinch but permit feeding of the tube between each other.

5. Apparatus according to claim 3, comprising means for mounting the closure and clamping jaws so that the closure jaws are operative and the clamping jaws are not effective to clamp the leading tube end whenever the tube is being fed.

6. Apparatus according to.claim 2 comprising means for operating the clamping jaws with the aid of the sealing jaws and severing blades so that movement of the clamping jaws is executed with the aid of the severing blades and pivotal movement of the clamping jaws is executed with the aid of the sealing jaws.

7. Apparatus according to claim 2, wherein the clamping jaws overlap when they are effective to clamp the leading tube end.

8. Apparatus according to claim 7, comprising means for mounting the clamping jaws for relative reciprocation together with the severing blades and means for mounting one of the clamping jaws so that it places the leading tube end under the lower clamping jaw, where'- after the lower clamping jaw is adapted to swing upwardly so that the leading tube end is clamped between the clamping jaws.

9. Apparatus according to claim 3, wherein the closure jaws and clamping jaws have a width which is at least equal to the width of the flattened tube. 

1. A packaging machine in which an intermittently fed tube of packaging material is filled with a liquid substance and subdivided into individual packages by pinching the tube and transversely sealing it at intervals along its length, comprising a pair of sealing jaws mounted at a fixed horizontal position for intermittently applying a transverse sealing zone to the tube, a pair of severing blades for severing a filled and sealed leading portion of the tube by cutting through the said sealing zone to leave the then leading tube end sealed, closure means operative intermittently to pinch the tube shut upstream of the said sealing zone and thereby intermittently interrupt the flow of liquid substance, said closure means being operable to effect interruption of said flow as said pinched tube is fed through said operative closure means, clamping means effective to support the leading tube end and to clamp said sealing zone when the closure means are in-operative and the leading tube end is being filled with liquid, whereby said sealing zone is clamped during the filling operation to permit said sealing zone to cool and set and thereby withstand the mechanical stresses caused by the weight of the liquid in the package, and means for opening said clamping means to permit said filled package to be lowered as said pinched tube is fed through said operative closure means.
 2. ApparatuS according to claim 1, wherein the clamping means comprise two clamping jaws which are pivotable about parallel axes and connected to the severing blades so as to receive the leading tube end between each other when the severing blades have cut through the sealing zone.
 3. Apparatus according to claim 2, wherein the closure means comprise two jaws, at least one of which is pivotable to and from the operative position at which the flow of the liquid substance is interrupted.
 4. Apparatus according to claim 3, wherein each jaw of the closure means comprises a roller, the rollers being adapted to pinch but permit feeding of the tube between each other.
 5. Apparatus according to claim 3, comprising means for mounting the closure and clamping jaws so that the closure jaws are operative and the clamping jaws are not effective to clamp the leading tube end whenever the tube is being fed.
 6. Apparatus according to claim 2 comprising means for operating the clamping jaws with the aid of the sealing jaws and severing blades so that movement of the clamping jaws is executed with the aid of the severing blades and pivotal movement of the clamping jaws is executed with the aid of the sealing jaws.
 7. Apparatus according to claim 2, wherein the clamping jaws overlap when they are effective to clamp the leading tube end.
 8. Apparatus according to claim 7, comprising means for mounting the clamping jaws for relative reciprocation together with the severing blades and means for mounting one of the clamping jaws so that it places the leading tube end under the lower clamping jaw, whereafter the lower clamping jaw is adapted to swing upwardly so that the leading tube end is clamped between the clamping jaws.
 9. Apparatus according to claim 3, wherein the closure jaws and clamping jaws have a width which is at least equal to the width of the flattened tube. 